ils ne laisseront

they won't let

→ il
phrase Rare #42,378
they won't let Usually followed by an infinitive describing what they will not allow someone to do.
FR: Ils ne laisseront pas les enfants jouer dehors.
EN: They won't let the children play outside.

Ils ne laisseront pas Tom entrer.

They won’t let Tom in.

Ils ne laisseront pas Tom s'échapper.

They won't let Tom escape.

Ils ne laisseront pas sortir Tom.

They won't let Tom out.

Ils ne laisseront jamais leur terre.

They will never abandon their land.

— Avatar (2009)